| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
|
| Presentation Title |
Magnetic Properties of Non-Crystalline Ho2Ti2O7 Pyrochlore Prepared by Far-From-Equilibrium Processing |
| Author(s) |
Cale C. Overstreet, Eric O'Quinn, Yishu Wang, Maik Lang |
| On-Site Speaker (Planned) |
Cale C. Overstreet |
| Abstract Scope |
Rare-earth pyrochlore oxides (RE2B2O7) can exhibit unique magnetic ordering due to geometric frustration competing interactions between the antiferromagnetic exchange and dipolar interaction. However, little is known about the impact of far-from-equilibrium processing on magnetic properties and the associated energetics. We processed Ho2Ti2O7 with 1.47 GeV gold ions at the GSI Helmholtz Center and synthesized a sample via mechanochemistry within a ball mill. The resulting materials were characterized using synchrotron-based X-ray total scattering experiments at the National Synchrotron Light Source II and DC magnetic susceptibility measurements. X-ray diffraction confirmed a highly disordered and amorphous state in both processed samples, while the DC susceptibility revealed a distinct change in magnetic behavior which is characteristic of local atomic ordering. Previous neutron scattering revealed that amorphous pyrochlore locally exhibits weberite-type ordering; high temperature structural analysis and calorimetry show this local phase persists well beyond the long-range recrystallization and recovery of the original magnetic state. |